Add 4th Gen input controls

src/widget-label.h

@@ -0,0 +1,10 @@
+// SPDX-FileCopyrightText: 2022 Geoffrey D. Bennett <g@b4.vu>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include <gtk/gtk.h>
+
+#include "alsa.h"
+
+GtkWidget *make_label_alsa_elem(struct alsa_elem *elem);